New FT Explorer

[Andy.T.]

So I got to take my FT Explorer up for it's maiden today. I was pretty happy with how it flew, but feel like I might be spoiled with MM FT Zero's ability to accelerate going straight up with the power pack F. I had almost no trimming that was super obviously necessary. For this Explorer I was trying (3s) an orange motor I got on Amazon, and a 9x6 prop. I had thought it was going to be pretty equivalent to a Power Pack C motor, but I really don't know what to expect as far as handling. My Explorer at time felt like it, maybe not struggled, but, I didn't feel like it had power for anything. I wasn't expecting to have to fly at 3/4 - full throttle as much as I did and still have to climb somewhat sparingly. So first question, should I maybe be expecting to have to fly with the throttle 2/3 - full mostly? Or maybe this 56" wing just makes that much drag, or I guess, I built it too heavy somehow?

Next area of question is weight and balance. I was flying w/ a GensAce 3s 3300mah pushed as far forward as I dared. It barely balanced not tail heavy at the suggested CG. Usually I have found I like to fly a little forward of what suggested CG is listed with (a trend I've noticed on 4 or 6 planes). Having to use such a big battery to make it balance even maybe at an almost comfortable CG surprised me, especially given that it felt a little like I could have added a little more weight in the nose. Does this mean for some reason perhaps my tail section is too heavy? There were a few times in my first flight where I swear it felt like I was flying at a consistent altitude but slightly nose up. It was, windier than I expected based on weather I saw, but figured it'd be able to handle ~10mph winds. But most of the times it seemed to fly just fine. Follow-up question, does that amount of tail heavy really make sense? I was honestly expecting to be able to fly w/ a 2200mah, but with ~100g less battery up front, I'd definitely have to add extra weight to the nose. Just super curious how this matches others' FT Explorer experience.
Another minor point I found interesting, I added a BBQ skewer thru the fuselage and tail boom hoping it would help it flex less. I'm pretty sure the first time I launched it, the prop actually struck the tail boom, and caused the ESC to going into a failsafe mode; I had to unexpectedly land w/o power about 15 seconds after launch.

The paint...Rustoleum spray paint, both the blue and fluorescent green flaked off SUPER easy. I'm thinking maybe I'll re-apply and then coat w/ poly. Does this sound like a thing people have seen before?

 

[kdobson83]

Definitely sounds like your a bit heavy. Especially if your using a 3300 pushed all the way forward. My Explorer used a 2200 right where the plans show and it balanced fine. Do you have a kitchen scale? What's your dry weight?

I was using a racerstar 2216 1400kv with a 9x5 prop on mine. It had unlimited vertical using a 3s 2200. Do you have any of the actual specs on the motor your using? Size? KV?

Be careful adding more paint. More paint = more weight. Over my 8 years of building, I have found two methods work great.

Method 1 - Using a foam brush or a paper towel, I brush on a light coating of Oil Based Minwax onto any piece that will be on the outside of the plane (no need to put on inside parts). And then blue painters tape (removing some of the sticky by first sticking to my shirt a few times). The Minwax will make the foam waterproof and helps the spray paint stick, it also prevents the paper from sucking up the paint if I apply to heavily and delaminating. Make sure you use "OIL" based, and not water based minwax. The water based will work, but will also delaminate if you put too much on. The only drawback to this method is any parts not getting paint will yellow, almost to the point where you have to paint over the white components with white paint.

Method 2 - I got some really thin/light weight packing tape from Amazon. I paint using very light coats before I build (parts are still kit form) and then apply the clear thin packing tape while the parts are still flat. You can just put on strips that are a few inches longer than the parts and then run a box knife around the edges to cut off the excess. Again, only add tape to the parts that are visible. This adds TONS of strength/durability and will be mostly water resistant. The only drawback with this method is the packing tape does add weight, but the super thin stuff I got only adds maybe 10-20 grams for a plane the size of the tutor. I used this method in the pictures below. You can see that the tape method makes it a little shiny, so if your going for a mat look, this method isn't the best.

I used the tape method on all my builds now.

 

[Clintonious]

Definitely sounds like your a bit heavy. Especially if your using a 3300 pushed all the way forward. My Explorer used a 2200 right where the plans show and it balanced fine. Do you have a kitchen scale? What's your dry weight?

I was using a racerstar 2216 1400kv with a 9x5 prop on mine. It had unlimited vertical using a 3s 2200. Do you have any of the actual specs on the motor your using? Size? KV?

Be careful adding more paint. More paint = more weight. Over my 8 years of building, I have found two methods work great.

Method 1 - Using a foam brush or a paper towel, I brush on a light coating of Oil Based Minwax onto any piece that will be on the outside of the plane (no need to put on inside parts). And then blue painters tape (removing some of the sticky by first sticking to my shirt a few times). The Minwax will make the foam waterproof and helps the spray paint stick, it also prevents the paper from sucking up the paint if I apply to heavily and delaminating. Make sure you use "OIL" based, and not water based minwax. The water based will work, but will also delaminate if you put too much on. The only drawback to this method is any parts not getting paint will yellow, almost to the point where you have to paint over the white components with white paint.

Method 2 - I got some really thin/light weight packing tape from Amazon. I paint using very light coats before I build (parts are still kit form) and then apply the clear thin packing tape while the parts are still flat. You can just put on strips that are a few inches longer than the parts and then run a box knife around the edges to cut off the excess. Again, only add tape to the parts that are visible. This adds TONS of strength/durability and will be mostly water resistant. The only drawback with this method is the packing tape does add weight, but the super thin stuff I got only adds maybe 10-20 grams for a plane the size of the tutor. I used this method in the pictures below. You can see that the tape method makes it a little shiny, so if your going for a mat look, this method isn't the best.

I used the tape method on all my builds now.

View attachment 236555

View attachment 236556

So for clarification, what method did you use on that little beauty?

 

[Andy.T.]

Definitely sounds like your a bit heavy. Especially if your using a 3300 pushed all the way forward. My Explorer used a 2200 right where the plans show and it balanced fine. Do you have a kitchen scale? What's your dry weight?

I was using a racerstar 2216 1400kv with a 9x5 prop on mine. It had unlimited vertical using a 3s 2200. Do you have any of the actual specs on the motor your using? Size? KV?

Be careful adding more paint. More paint = more weight. Over my 8 years of building, I have found two methods work great.

Method 1 - Using a foam brush or a paper towel, I brush on a light coating of Oil Based Minwax onto any piece that will be on the outside of the plane (no need to put on inside parts). And then blue painters tape (removing some of the sticky by first sticking to my shirt a few times). The Minwax will make the foam waterproof and helps the spray paint stick, it also prevents the paper from sucking up the paint if I apply to heavily and delaminating. Make sure you use "OIL" based, and not water based minwax. The water based will work, but will also delaminate if you put too much on. The only drawback to this method is any parts not getting paint will yellow, almost to the point where you have to paint over the white components with white paint.

Method 2 - I got some really thin/light weight packing tape from Amazon. I paint using very light coats before I build (parts are still kit form) and then apply the clear thin packing tape while the parts are still flat. You can just put on strips that are a few inches longer than the parts and then run a box knife around the edges to cut off the excess. Again, only add tape to the parts that are visible. This adds TONS of strength/durability and will be mostly water resistant. The only drawback with this method is the packing tape does add weight, but the super thin stuff I got only adds maybe 10-20 grams for a plane the size of the tutor. I used this method in the pictures below. You can see that the tape method makes it a little shiny, so if your going for a mat look, this method isn't the best.

I used the tape method on all my builds now.

View attachment 236555

View attachment 236556

Good looking plane! I looks like it would fly well.
Thanks for the thoughts. I may well have built my Explorer too heavy. Motor I have on there currently is a Flash Hobby 1120KV motor 14 pole 12 slot. To be honest, I thought I had intended on getting the same Flash Hobby D2836 but in 1500kv. Or maybe I just thought that would be close enough to a power pack C's Radial 2218 1180kv. Anyways, it's got a 9x6 prop on it currently.

I kept track of the weight of the nose + fuse + boom + tail assembly from final build (with servos, but no radio, motor, power pod, esc) and then initial coat of oil based Minwax poly, and then now after painted and already flew a couple times (I took out same above bits).
The nose gained 2.7g of poly. Then 5.3g with paint. Not taking into all the pain on the bottom that flaked off pretty readily after landing on the melting snow. Ending weight of the nose 33.g.
The fuse and boom/tail assembly, less radio, esc, motor, power pod, gained 3.1g of poly, then gained 31.5g of paint. Total weight 241g.
The power pod with motor, prop, esc, and the pod itself with paint is 150g. The wing's final weight with paint and servos is 290g.
Total Explorer weight currently is about 714.2g without the battery. I think that's a couple hundred grams above the listed weight of the Explorer. Maybe that's part of the issue too. There might be a 1500kv on the way from amazon. Interested to see if I can swap it and see a difference.

 

[kdobson83]

So for clarification, what method did you use on that little beauty?

I used the thin packing tape method on this one. Painted first using 3-4 very light coats, the wife cut out the decals with her cricut, and then tape. I use U-Line tape part number s-423. I found a 6 pack on Amazon for $20. Its not 100% clear and can tell its got tape on it when your up close, but its not bad and the cost of weight it adds is negligible with the benefit of added strength and durability.

 

[kdobson83]

Good looking plane! I looks like it would fly well.
Thanks for the thoughts. I may well have built my Explorer too heavy. Motor I have on there currently is a Flash Hobby 1120KV motor 14 pole 12 slot. To be honest, I thought I had intended on getting the same Flash Hobby D2836 but in 1500kv. Or maybe I just thought that would be close enough to a power pack C's Radial 2218 1180kv. Anyways, it's got a 9x6 prop on it currently.

I kept track of the weight of the nose + fuse + boom + tail assembly from final build (with servos, but no radio, motor, power pod, esc) and then initial coat of oil based Minwax poly, and then now after painted and already flew a couple times (I took out same above bits).
The nose gained 2.7g of poly. Then 5.3g with paint. Not taking into all the pain on the bottom that flaked off pretty readily after landing on the melting snow. Ending weight of the nose 33.g.
The fuse and boom/tail assembly, less radio, esc, motor, power pod, gained 3.1g of poly, then gained 31.5g of paint. Total weight 241g.
The power pod with motor, prop, esc, and the pod itself with paint is 150g. The wing's final weight with paint and servos is 290g.
Total Explorer weight currently is about 714.2g without the battery. I think that's a couple hundred grams above the listed weight of the Explorer. Maybe that's part of the issue too. There might be a 1500kv on the way from amazon. Interested to see if I can swap it and see a difference.

OK, so, You are definitely heavier than stock. The spec sheet on the explorer says they should be about 500 grams without battery. Your about 215 grams over that. I wouldn't think you added 215 grams of paint though. What brand foam board did you use? The 3300 gens ace battery your using is about 252 grams per their website. Your sitting at about 1000 grams give or take.

That motor, according to their website, has a max thrust of about 1130 grams, but they have it listed with suggested props of 7-11". So this 1130 grams they advertise is probably using the 11" prop. You've got a 9", and 9" is about as big as will fit. I had a 9" on my explorer and it maybe had 1/2 a mm clearance from the boom. Using your 9" prop on that motor, I'd guess your getting maybe 800-900 grams of thrust.

So, Plane = 1000grams wet, Your thrust = 900ish grams. My opinion, your lacking power. This would explain you having to fly at 2/3 to full throttle. The Explorer is limited to only using 9" or smaller props. So your only real option to increase your thrust to weight ratio using that motor is to add volts. But I'm not sure if those motors can use 4s batteries. They have them listed as 7.4-11.1volts.

That 1500kv motor you said you might get shows suggested props of 7-9" and a max thrust of 1150grams. So in theory, should fix your power issue somewhat. I personally like to use motor/prop combos that will produce at least 50% more power than the AUW of the plane. In your scenario, you'd need about 1500grams of thrust. But this is just my opinion.

Sorry for the long replies, I'm bored at work. lol

 

[Edgit]

I too have a weight problem, my explorer requires about 150 gram nose weight to balance at the recommended CG . Guess this may be due to the white foamboard used, about 320 gram over suggested weight. Not sure what I should do, put in the nose weight or shorten
fuselage? Any help appreciated please, Alan

 

[Andy.T.]

OK, so, You are definitely heavier than stock. The spec sheet on the explorer says they should be about 500 grams without battery. Your about 215 grams over that. I wouldn't think you added 215 grams of paint though. What brand foam board did you use? The 3300 gens ace battery your using is about 252 grams per their website. Your sitting at about 1000 grams give or take.

That motor, according to their website, has a max thrust of about 1130 grams, but they have it listed with suggested props of 7-11". So this 1130 grams they advertise is probably using the 11" prop. You've got a 9", and 9" is about as big as will fit. I had a 9" on my explorer and it maybe had 1/2 a mm clearance from the boom. Using your 9" prop on that motor, I'd guess your getting maybe 800-900 grams of thrust.

So, Plane = 1000grams wet, Your thrust = 900ish grams. My opinion, your lacking power. This would explain you having to fly at 2/3 to full throttle. The Explorer is limited to only using 9" or smaller props. So your only real option to increase your thrust to weight ratio using that motor is to add volts. But I'm not sure if those motors can use 4s batteries. They have them listed as 7.4-11.1volts.

That 1500kv motor you said you might get shows suggested props of 7-9" and a max thrust of 1150grams. So in theory, should fix your power issue somewhat. I personally like to use motor/prop combos that will produce at least 50% more power than the AUW of the plane. In your scenario, you'd need about 1500grams of thrust. But this is just my opinion.

Sorry for the long replies, I'm bored at work. lol

I sympathize deeply with both long replies and bored at work. Maybe bored with work more than at work; work is intense lately.
I was estimating my power slightly higher than you were I think. My rough mental perspective was in the lines of 1.1kg of thrust. Partially because assuming voltage at 4v per cell, kinda in the middle of the village they seem to be when I fly. But also because prop is 9x6, not 9x4.5. I don't think I found any numbers for x6 pitch'd props. My little scale I think only goes up to 1kg. I might have to borrow a buddy's. I think I could run the motor with the prop on the scale and actually measure how much thrust. That is a really exciting idea. I love gathering data like that. And then I can compare with the 1500kv motor when it arrives.
I am pretty sure I saw mention of these motors being good for 2-4s. Even if they were only rated up to 3s, I bet I could run them, at least for a short while, higher than listed. In another hobby not flying related, we abuse motors pretty hard, using them for not quite their intended purposes; not afraid to actually use up a motor and replace it. I just might start buying a couple 4s batteries. Seems like a thing I'd like on hand anyways.
Definitely agree that I must be heavy. I used the FT Speed build kit. It's white maker foam I believe. I wonder if I build with too much hot glue. I've also often gone over some exposed edges with a beed of hot glue, thinking it would help hold the foam board together, add strength, etc. Maybe that is a poor choice tho. I guess if the paint added was measurable (I figure 45g that I can account for in nose and fuse, and estimate another 20-30g on the wing), the amount of glue used, especially for something like lining the exposed edges of foam board, that could easily account for another hundred or two grams of extra weight. I'll have to be more cognizant of thinking light with everything I do during builds. Definitely going to look into your extra light packing tape. That seems like it solves multiple problems, including weight minimizing.

 

[Andy.T.]

I too have a weight problem, my explorer requires about 150 gram nose weight to balance at the recommended CG . Guess this may be due to the white foamboard used, about 320 gram over suggested weight. Not sure what I should do, put in the nose weight or shorten
fuselage? Any help appreciated please, Alan

I used ft speed build kit on my. I just assumed the weight would be fine given that. But as I mentioned in other reply, I am wondering if I have been too heavy with a lot of my glueing. Not that that helps you.
Shortening the boom absolutely crossed my mind. But, it was so tough to get in, I didn't want to take the boom out again. Another thing I must have done slightly weird on my build; the boom was just such I tight fit that I ended up adding all sorts of creases in the foam trying to shove it in. I think for tail heavy, that is about what you can do. Lighten tail weight. Shorten how far back it sticks. Add nose weight.
I'm still learning with everything I do tho. There's many smarter people here than I.

 

[Piotrsko]

I too have a weight problem, my explorer requires about 150 gram nose weight to balance at the recommended CG . Guess this may be due to the white foamboard used, about 320 gram over suggested weight. Not sure what I should do, put in the nose weight or shorten
fuselage? Any help appreciated please, Alan

How about carefully drilling a bunch of 17 mm diameter spade bit holes in the aft fuselage sides top and bottom and covering them with one light layer of thin tape? Ditto for the tail feathers. Might look like swiss cheese, but it will lighten stuff up a fair amount. Probably too much glue used back there. Can you move the electronics forward much?

 

[Edgit]

I used ft speed build kit on my. I just assumed the weight would be fine given that. But as I mentioned in other reply, I am wondering if I have been too heavy with a lot of my glueing. Not that that helps you.
Shortening the boom absolutely crossed my mind. But, it was so tough to get in, I didn't want to take the boom out again. Another thing I must have done slightly weird on my build; the boom was just such I tight fit that I ended up adding all sorts of creases in the foam trying to shove it in. I think for tail heavy, that is about what you can do. Lighten tail weight. Shorten how far back it sticks. Add nose weight.
I'm still learning with everything I do tho. There's many smarter people here than I.

Thanks Andy, interesting in your reply thought it was only me with a heavy Explorer

 

[Edgit]

How about carefully drilling a bunch of 17 mm diameter spade bit holes in the aft fuselage sides top and bottom and covering them with one light layer of thin tape? Ditto for the tail feathers. Might look like swiss cheese, but it will lighten stuff up a fair amount. Probably too much glue used back there. Can you move the electronics forward much?

Thanks for your thoughts on my problem, all electronics are far forward as possible and can fit a 3000mah battery, I think drilling 17mm holes is a very good idea and well solve the issue. Will let you know of my progress, Alan

 

[Andy.T.]

How about carefully drilling a bunch of 17 mm diameter spade bit holes in the aft fuselage sides top and bottom and covering them with one light layer of thin tape? Ditto for the tail feathers. Might look like swiss cheese, but it will lighten stuff up a fair amount. Probably too much glue used back there. Can you move the electronics forward much?

Whoa, are you suggesting adding holes to the tail boom and tail surfaces?! Could that weaken the boom enough to make it flex? Would the stabilizers still stabilize? I suppose that's what the tape helps, on both accounts. That would be an interesting experiment to see how much weight that would cut down.

 

[Piotrsko]

Yuppa adding some 3/4" diameter holes in a structure that's bigger than 3/4" makes it way lighter and not necessarily weaker. Tape does add noticeable strength. It if gets too weak you went overboard and if I try, all my foamboard fuselages wobble and flex. Was all the rage back in the 1930's aircraft and 1950 hotrods.

 

[JDSnavely]

Remember the FT video where Josh and Josh took turns cutting holes (no tape) into a plane. The winner was the last one flying and landing after cutting a hole. I would never have thought a plane with that much damage could still fly. With tape maybe, but not their plane.

 

[Andy.T.]

Well, I got to fly with the 1500kv motor, briefly. Amount of power seemed much better, perhaps even good. But, the wing started flexing, was looking pretty dicey, and then collapsed! When I rebuild, I am planning on leaving out the dihedral, and using a carbon fiber tube as added spar reinforcement. I used a couple pieces of some wooden dowel, but having a break in the middle, albeit with the ends as close as I could get them, obviously wasn't enough.

so this leads me to next question. How would I go about getting the plans to rebuild the wing and the nose? I have not been able to find plans for the Explorer.
<edit> Sorry, I guess I needed to keep looking. Found in the Articles section. That looks to be what I need.

 

[JDSnavely]

SP0NZ - Plans Index

Printing Tips: https://www.flitetest.com/articles/printing-flite-test-plans AIO = All-In-One: Includes Full-Size, A-Size (7.5 x 10.5), and B-Size (10.5 x 15) plans in one file FS = Full-Size: 34 x 22 non-tiled plans (fits ANSI D and ISO A1, requires a large format plotter) * TA = Tiled...

forum.flitetest.com

The plans are here.

 

[Andy.T.]

So, the new wing on my Explorer seems to have held up to it's first few minutes of flight. No immediately obvious bad stress marks.
BUT, the motor was not happy. I don't think it's reusable. I'll link it below, but, was using a the 1500kv Flash Hobby 2836 and a 9x6 prop. After that few minutes of flying, the motor was almost too hot to touch. After it cooled, it does not spin very freely anymore. Do you guys think maybe the 9x6 prop was too aggressive for it, and I burned out the motor?

https://www.amazon.com/dp/B08M8VS47Y/?tag=lstir-20

 

[quorneng]

According to this site the 1500kv Flash Hobby 2836 is ok with a 9x6 but only with a 3s. For 4s it needs a 7x3.
If you are using a 3s LiPo then the motor getting hot suggests there is something amiss with it. It now looks like it is in an even worse and will have to be replaced.

 

[Andy.T.]

According to this site the 1500kv Flash Hobby 2836 is ok with a 9x6 but only with a 3s. For 4s it needs a 7x3.
If you are using a 3s LiPo then the motor getting hot suggests there is something amiss with it. It now looks like it is in an even worse and will have to be replaced.

Yes, I was running it on a 3s LiPo. I had thought it would be ok w/ the 9x6, but had, obviously, started to doubt myself. I thought maybe I picked too cheap of a motor. I can't think of any other factors at all. Voltage was within range, prop selection should have been fine, battery was nothing special, just a 3300mah 3S - brandnew, and ESC was 40amp FT ESC. What else am I missing? Does the weight of the plane actually matter here?